基于节点构形度的单层柱面网壳稳定优化设计

摘要

Stability is a key factor in design and analysis of single-layer cylindrical domes.From the perspective of joint well-formedness,the relative gradient of joint well-formedness (gra_r) was defined here to fully reflect the static stability of structures and consider the core part directly related to stability of external factors,its minimum value (gra_rmin) Was directly related to stability loads.It was shown that gra_r can quantitatively measure a structure's tendency to lose stability and reveal domes' unstable mechanism.On this basis,the stability optimization design method for singlelayer cylindrical domes was proposed.Using the stability optimization model,the maximization of gra_rmin was taken as an objective,and discrete rods' cross-sections as variables,various design constraint conditions specified in the code were considered,the force-bearing ability for the structure stability was improved under the premise of a given steel-consuming amount.Two practical engineering examples verified the effectiveness of the proposed stability optimization design method for single-layer cylindrical domes.%稳定是单层柱面网壳结构分析与设计中的关键因素.从节点构形度的视角,考虑外在因素中与稳定问题直接相关的核心部分,定义了能全面反映结构静力稳定特性的节点构形度相对变化梯度(gra_r),其最小值(gra_rmin)与稳定承载力直接相关.gra_r能定量地衡量结构丧失稳定的趋势,揭示网壳结构失稳机理.在此基础上,进一步提出了单层柱面网壳稳定优化设计方法.稳定优化模型以gr a_rmin最大化为优化目标,离散的杆件截面为优化变量,考虑规范规定的各项设计约束条件,在给定用钢量的前提下,提高结构稳定承载力.两个实际工程算例验证了单层柱面网壳稳定优化设计方法的有效性.